[en] The study of scientific images opens up new horizons for semiotic reflection, if only because of the two practical functions commonly attributed to these images: a specific cognitive function and an experimental function. They have a cognitive function in the sense that they facilitate a better understanding of the things they represent, or imprint. Of course this is also true of a photograph used in an investigation, which provides information that may eventually lead to the thing of which it is an index, but its referent is part of the shared world of perception, and is consequently identifiable independently of the image. Conversely, in contemporary scientific practice, the image is supposed to manifest something that is not necessarily known prior to imaging it, and consequently, shaping the image also entails shaping the cognitive object. The cognitive function of the scientific image is therefore primarily prospective, and in some ways predictive.